Intraspinal synovial cysts presenting with lower back pain and radiculopathy are well known but rare. They are associated with facet joint arthopathy, generally degenerative in nature. Spinal synovial cysts have not been described in spondyloarthropathies (SpA). We report a case of a 66-year-old man with a chronic undifferentiated SpA who presented with severe weakness of both legs. A centrally located spinal cyst was encountered on MRI and led to excision of a highly inflammatory synovial cyst. This association may not be fortuitous and be related to inflammation of the facet joint in SpA.